Here's a few things to keep in mind. The sound board aids in the roll over in the call. Get it too far away from the surface and the call will be flat. Get it too close and it will be high pitch to screechy almost and not much roll over. Get some glue in between the sound board and the inside of the pot or the sound board and the call will be flat. If you want a loud call make your holes larger. Quiet call = less holes and/or smaller holes and/or no holes.
The deeper the pot the more hollow sound the call will produce. Thinner the pedestal the more rasp the call will produce if you did everything else right.
If you want a decent sounding 3" call don't make the pot real deep and keep the sound board close to the underside of the top surface. Slate, Glass, and Aluminum keep the bottom of the pot about 1/4" thick for a 3" surface. For a 3.5" surface it doesn't matter the thickness of the bottom and yes I can prove that. Rule of thumb is 3.5" surface use a 3" sound board and on the 3" surfaces use a 2.5" sound board. If you want the call to have a low sounding pitch use a heavy striker and if you want the sound to be higher pitched then lighten the weight of your striker. The harder the sound board material the sharper the yelps will be as in faster roll over assuming you did everything else right. Wood and slate sound boards will mellow the yelps out or in other words slow the roll over down.
Larry